Diabetes Mellitus More Prevalent In Psychiatric Patients Than General Population

The prevalence of diabetes and impairment in glucose metabolism are noticeably higher in psychiatric patients.

Diabetes mellitus (DM) appears to be more prevalent in the psychiatric setting than in the general population, according to the results of a recent meta-analysis from the United Kingdom published earlier this year in General Hospital Psychiatry.1Both inpatients and outpatients with psychiatric conditions were more likely to have a diagnosis of DM, or to have impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) than patients without a psychiatric condition.2,3

The investigators evaluated 36 studies from Europe, Asia, and North America involving 42 psychiatric cohorts for the prevalence of multiple impairments of glucose metabolism. Unspecified DM was reported in 10% of all patients evaluated from 31 studies (95% CI, range 9-12), while the prevalence of type 1 DM was 1% (0-1) and type 2 DM was 9% (613) reported in 5 and 13 studies, respectively. The prevalence of IFG was 18% (8-28, 7 studies), and of IGT 22% (16-28, 3 studies). This meant that 1 of every 10 psychiatric patients studied was diagnosed with DM, 1 in 5 with IFG, and 1 in 5 with IPG. The prevalence rates did not vary by continent or by type of inpatient setting.

The range of psychiatric diagnoses included schizophrenic or schizoaffective disorders, mood disorders, and substance abuse disorders, with little variation in prevalence of unspecified DM by psychiatric category (11% across all inpatient disorders, 95% CI, 10-12).

The etiology of this increased prevalence was not clear, although the investigators suggested that links to antipsychotic medication use in these patients could be a factor.4,5 “The study did not set out to examine the etiology of abnormal glucose metabolism in these patients, but to document its prevalence in these settings,” study co-investigator, Emmert Roberts, MA, BMBCh, MRCP (UK), MRCPsych, DFSRH, of the Institute of Psychiatry, Psychology and Neuroscience at King's College London, in the United Kingdom, told Psychiatry Advisor.

The study findings indicated a need for psychiatrists to give attention to their patients' glucose metabolism status. “We would recommend that routine screening take place in psychiatric inpatient settings for not only DM but also pre-diabetic states of abnormal glucose metabolism,” Dr. Roberts said. The researchers contend that such screening would present opportunities for timely intervention with metabolic issues that might be contributing to psychiatric illnesses. “A prevalence of 1 in 5 for IFG or IGT is higher than estimates for number of inpatients with bipolar affective disorder and some personality disorders across all inpatient settings, suggesting that abnormal glucose metabolism should be an essential part of psychiatric postgraduate examination, training and expertise,” they concluded.

Given the high risk for metabolic disorder and type 2 diabetes, clinicians should select psychotropic medications carefully and monitor metabolic conditions regularly in their patients with serious mental illness.

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